Rolls of light sensitive paper and film require light-tight packaging so that they are not exposed to daylight prior to use. However, the rolls should be packaged such that they can be loaded into co-operating apparatus under daylight conditions.
U.S. Pat. No. 4,148,395 discloses a package including a pair of flexible opaque end discs or covers attached to the ends of a core of the roll, and an opaque leader attached to a leading end of the length of material forming the roll. A peripheral portion on each end disc is folded over and adhered to an edge of an underlying convolution of the leader. A layer of adhesive is provided on the underside of the peripheral portion prior to folding over. As the leader is pulled away from the roll the end discs tear circumferentially at the edge of the roll, the peripheral portions remaining adhered to the leader.
U.S. Pat. No. 5,133,171 discloses a package which includes a pair of opaque flexible end discs attached to the ends of the core of the roll of material and an opaque leader attached to the leading end of the length of material forming the roll. After a first convolution of the leader is wrapped onto the roll peripheral portions of each end disc are folded over the first convolution. A second convolution is then wrapped onto the roll to capture the folded over portions between the first and second convolutions of the leader. No adhesive is used, friction being relied upon to hold the folded over portions between the convolutions.
U.S. Pat. No. 5,515,970 discloses a package having similar opaque end discs and leader. In this case the folded over portions of the end discs are held in place by adhesive tape strips. In both packages the end discs tear circumferentially at the edge of the roll when the leader is pulled.
Each disc has a central hole. The diameter of the central hole is smaller than the diameter of the core. The inner diameter edge of each disc is folded into the hollow core and secured to the inner wall using any suitable means. To facilitate attachment a plurality of radial cuts are made at the inner diameter edge of the disc. The cuts define a plurality of tabs which can be folded into the bore of the core along the inner wall. However, due to the inherent flexible and flimsy nature of the discs these cuts may tear and propagate to the end of the roll, thereby permitting the entry of light into the package.
The end discs of the light-tight package must be tearable when the leader is pulled. However it is also a requirement that the disc does not tear at the inner diameter portion which is adhered to the core. The invention therefore aims to provide a method of sealing the inner diameter portion of the disc to the inner wall of the core which reduces the possibility of the disc tearing at this point while still utilising a material which allows circumferential tearing.